Authors:Jing Tong; Xu Zheng; Jian Tong; Ye Qu; Lu Liu; Hui LiAbstract: Abstract The values of density and surface tension for aqueous solution of ionic liquid(IL) 1-butyl-3-methylimidazolium acetate([C4mim][OAc]) with various molalities were measured in the range of 288.15—318.15 K at intervals of 5 K. On the basis of thermodynamics, a semi-empirical model-molar surface Gibbs energy model of the ionic liquid solution that could be used to predict the surface tension or molar volume of solutions was put forward. The predicted values of the surface tension for aqueous [C4mim][OAc] and the corresponding experimental ones were highly correlated and extremely similar. In terms of the concept of the molar Gibbs energy, a new Eötvös equation was obtained and each parameter of the new equation has a clear physical meaning.PubDate: 2017-09-16DOI: 10.1007/s40242-017-6386-5

Authors:Yanhong Ma; Yan Jiang; Yuan Liang; Weiwei Zhang; Hongwen Zhang; Rong ZhangAbstract: Abstract The surface of poly(ethylene terephthalate)(PET) films is inert, hydrophobic, and incompatible with blood, which has limited its practical bioapplication. In this case, better biocompatibility could be achieved by surface modification. In this study, the grafted copolymer of functional methoxypolyethylene glycol(mPEG) derivatives and styrene from the PET surfaces was prepared via surface-initiated atom transfer radical polymerization(SI-ATRP). The structures, composition, properties and surface morphology of the grafted PET films were characterized by Fourier transform infrared spectroscopy(FTIR), X-ray photoelectron spectroscopy(XPS), contact angle measurements and scanning electronic microscopy(SEM). The results indicate that the surface of the PET films has been covered by a thick targeted copolymer layer that converted the hydrophobic surface of PET to an amphiphilic surface. The bacterial adhesion and cell culture results indicate the copolymer-grafted PET film may possess good biocompatibility.PubDate: 2017-09-16DOI: 10.1007/s40242-017-7032-y

Authors:Botao Zhang; Yang Zhang; Weixu Xiang; Yanguo Teng; Ying WangAbstract: Abstract The catalytic performances of different commercial cobalt oxides(Co x O y , i.e., Co2O3, Co3O4, and CoO) for peroxymonosulfate(PMS) activation in dye degradation were compared in this study. The CoO/PMS system exhibited the highest catalytic oxidation performances with more than 96% methylene blue(MB) removal at 90 min. The concentration of dissolved cobalt ions from CoO was 1.474 mg/L at neutral pH and 5.231 mg/L at acidic pH at 90 min which accounted for the high MB removal and CoO activated PMS homogeneously compared to the associated CoSO4/PMS. Co3O4 and Co2O3 exhibited similar catalytic performances and characteristics. The MB removal in Co3O4/PMS and Co2O3/PMS system were more than 88% at neutral pH and over 64% at acidic pH, respectively, in 90 min. The concentration of dissolved cobalt ions from Co3O4 and Co2O3 was less than 0.018 mg/L at neutral pH and 0.036 mg/L at acidic pH at 90 min. The MB removal achieved by Co3O4/PMS and Co2O3/PMS were approximately three times higher than that achieved by their associated CoSO4/PMS systems and the heterogeneous catalysis played a principal role in the processes. According to scavenger experiments, the contributions of the hydroxyl radicals in the MB degradation were negligible compared to sulfate radicals in the CoO/PMS system. Hydroxyl radicals contributed one-third or more and sulfate radicals were the dominant oxidizing species in the Co3O4/PMS and Co2O3/PMS systems. Co x O y could also effectively activate PMS to generate free radicals for degradation of other dyes. The dyedegradation processes in Co3O4/PMS, Co2O3/PMS and CoSO4/PMS systems followed pseudo-first-order kinetic model and dye degradation rates in different systems were also compared.PubDate: 2017-09-16DOI: 10.1007/s40242-017-6413-6

Authors:Yanjie Li; Xingmin Zhang; Shengxiu Niu; Yanping Zhao; Lijuan Yang; Xiaowei Shao; Ensi WangAbstract: Abstract A series of imidazo[4,5-c]quinoline derivatives(12a—12m) was synthesized with 2-amino-5-bromobenzoic acid and 4-nitrophenylacetonitrile as starting materials, 6-bromo-4-chloro-3-nitroquinoline as intermediate and Suzuki reaction and closure of the imidazolinone ring with triphosgene as key steps. The structures of the key intermediate and target compounds were confirmed by means of 1H NMR, 13C NMR and HRMS. These compounds show an interesting kinase profile as dual PI3K/mTOR tool compounds.PubDate: 2017-09-16DOI: 10.1007/s40242-017-7074-1

Authors:Lin Xu; Zhiming Zou; Huanhuan Zhang; Tongfei ShiAbstract: Abstract The swelling process of thin polystyrene films in quantity was studied in this paper using the in situ spectroscopic ellipsometry. We systematically investigated the influence of film thickness on the swelling process of thin polystyrene films. The results show that in the case of high M w polystyrene(M w=400000), the curve of the swelling degree as a function of time discloses that the relaxation of the long polymer chains accompanies the diffusion of acetone molecules. The swelling process is via the Fickian relaxation mechanism. Both the values of the equilibrium swelling degree and the diffusion coefficient of acetone molecules in the polystyrene film decrease as the film thickness reduces under confinement. However, in the case of low M w PS(M w=4100), the dewetting process is so fast before the equilibrium of swelling that the whole swelling process cannot be observed.PubDate: 2017-09-16DOI: 10.1007/s40242-017-7075-0

Authors:Chao Kong; Yanxia Han; Lijie Hou; Dongping Chen; Bowan WuAbstract: Abstract Ru nanoparticles were synthesized using the photoreduction and chemical reduction methods. Ru nanoparticles were used as a cocatalyst to develop a photocatalytic hydrogen evolution system sensitized by Eosin Y(EY), and the effects of the synthetic method and reductant on the morphology and photocatalytic hydrogen evolution per-formance of Ru nanoparticles were studied. The results indicated that Ru nanoparticles prepared by photoreduction and thermochemical reduction by ethanediol had a relatively uniform size, and the photoreduced Ru showed higher photocatalytic performance than Ru reduced by ethanediol and methanal. The amount of H2 evolution in 60 min over Ru(photoreduction)-EY was 1247.7 μmol, which was 13.6 and 14.3 times that over Ru prepared by chemical reduction methods under the same photoreaction conditions. The calculation of binding energies showed that a higher binding energy of Ru nanoparticles and glycol was one of the main reasons for the uniform size and low photocatalytic performance of Ru reduced by glycol. The results indicated that different preparation methods and reductants had a significant influence on the catalytic activity of Ru catalyst.PubDate: 2017-09-16DOI: 10.1007/s40242-017-6452-z

Authors:Rui Sang; Xu Cheng; Weijian Li; Pengfei Luo; Yong Zhang; Ruifang Nie; Li Hai; Yong WuAbstract: Abstract An efficient and ligand-free method for the Suzuki and Heck cross-coupling reactions has been success-fully developed using h-BN-supported palladium as the catalyst. This green methodology represents a cost-effective and operationally convenient process for the synthesis of biaryls, stilbenes and acrylates. Wide scope of substrates, good to excellent yields, low reaction time, water as solvent, ligand-free, non-toxicity and recyclability of the catalyst are the main merits of these protocols. In addition, the h-BN@γ-CD@Pd(II) nanomaterial has been fully characte-rized by TG, SEM, IR, XRD, XPS and ICP-AES analysis. And it could be easily recovered and reused for at least nine times without any considerable loss of catalytic activity. Above all, this work demonstrates the possibility of using cyclodextrin-modified h-BN as an efficient support for the hydrophilic heterogeneous catalysts.PubDate: 2017-09-16DOI: 10.1007/s40242-017-6455-9

Authors:Mengya Xie; Xiang Li; Yaping Ding; Guoxin ZhangAbstract: Abstract The phase equilibria for the MCl2-ThCl4(M: Mg, Ca, Sr, Ba) binary systems were critically evaluated and optimized based upon the CALPHAD approach. The substitutional solution model(SSM) was used to describe the liquid phase. All the intermediate compounds were treated as stoichiometric compounds of which Gibbs energies comply with the Neumann-Kopp rule. Thermodynamic model parameters optimization for respective phases was conducted by the least squares minimization procedure with required input data available from experimental mea-surements. Satisfactory agreements between all calculated results and experimental data were achieved which demonstrates that thermodynamic databases for the MCl2-ThCl4(M: Mg, Ca, Sr, Ba) binary systems were ultimately derived in the present work allowing safe extrapolation into multi-component system for guiding relative industrial applications.PubDate: 2017-09-13DOI: 10.1007/s40242-017-7033-x

Authors:Wenyu Cui; Lishuang Fan; Lin Geng; Maozhong An; Fujun ZhangAbstract: Abstract The use of a digital versatile disc(DVD)-based Ag electrode for the square-wave anodic stripping voltammetric determination of Pb2+ and Cd2+ was described. The effect of I– on the stripping analysis of Pb2+ and Cd2+ at Ag electrodes was first studied. I– significantly improved the stripping peaks of both Pb2+ and Cd2+. The square-wave voltammetric stripping response was linear over 5―50 μg/L for Pb2+ and Cd2+ with a deposition time of 118 s. The detection limits were 0.2 and 2.6 μg/L for Pb2+ and Cd2+, respectively. The high sensitivity, selectivity, and stability of this DVD-based Ag electrode enabled its practical application for simple, rapid and economical determination of trace levels of Cd2+ and Pb2+ in tap water samples. In addition, detection can be achieved without sample deoxygenation and the electrode can be easily manufactured.PubDate: 2017-09-13DOI: 10.1007/s40242-017-7010-4

Authors:Hongmei Zhang; Yan Liu; Fangping Ma; Wei Qiu; Bo Lei; Jinyou Shen; Xiuyun Sun; Weiqing Han; Jiansheng Li; Lianjun WangAbstract: Abstract Intramolecular hydrogen bonds(IMHBs) can lead to different physicochemical characteristics of nitro-phenols(NPs) that determine their environmental behavior. In the present work, to reveal the relationship between IMHB and nitrophenol reduction, the effects of IMHB on the molecular geometries and properties of a series of ni-trophenols were investigated with density functional theory(DFT) calculations. The results of the geometry optimiza-tion and atoms-in-molecules(AIM) analysis indicate relatively strong IMHBs in ortho-substituted nitrophenols, whose stability could be significantly improved. In comparing the E LUMO and adiabatic electron affinities(AEA) of the nitrophenol isomers, the presence of IMHBs benefited the reductive degradation of NPs, consistent with a previous study. To gain an insight into the effect mechanism of IMHBs on the reductive degradation behavior of these mole-cules, the condensed electrophilicity Fukui index(f –), natural charges and Wiberg bond orders of these nitrophenol isomers were calculated. The calculations indicate that the electrophilic reactivity activity of the O atom on the nitro group could be significantly improved due to the formation of IMHBs, which results in the enhanced reductive degradation of ortho-substituted NPs.PubDate: 2017-09-13DOI: 10.1007/s40242-017-7066-1

Authors:Yingmin Qu; Hao Yang; Songlin Wang; Tong Chen; Gongying WangAbstract: Abstract An environmentally friendly heterogeneous catalyst, C60-doped TiO2(denoted as C60-TiO2), was prepared and firstly used to catalyze the synthesis of diphenyl carbonate(DPC) via the transesterification of phenol and dime-thyl carbonate(DMC). The characterization results of FTIR, XRD, XPS, SEM, TEM and digital optical micro-scope(MIC) show that C60 promotes the dispersion of TiO2 and the prepared conditions affect the dispersion and the electron density of Ti species. The C60-TiO2-8[n(Ti):n(C60)=8:1] prepared with toluene and calcined at 200 °C exhi-bits the best catalytic performance. The DPC selectivity of 86.5% attained over C60-TiO2-8 was much higher than that(about 50%) attained over Ti-based catalysts reported, which was originated from the electronic effect of C60 and the efficient dispersion of Ti species by C60. The phenol conversion slowly decreased from 34.4% to 26.7% after four consecutive runs due to the leach of Ti species. It also suggested that the C60 could relieve the leach of Ti species compared with other Ti-based catalysts reported. Moreover, C60-TiO2-8 exhibited excellent catalytic behavior for disproportionation of methyl phenyl carbonate(MPC) with high DPC selectivity.PubDate: 2017-09-13DOI: 10.1007/s40242-017-6500-8

Authors:Xizhou Shen; Huajun He; Bowen Yang; Zhigang Zhao; Kaiyuan Shao; Wenxiang HuAbstract: Abstract In this paper, the activities of electrophilic sites on benzene ring of 4-substituted anilines and their acyl compounds were studied with the quantitative indicator of multiphilicity descriptor. Four substituents were synthe-sized with microwave irradiation in good yields to verify the quantitative analysis data. Friedel-Crafts acylation was carried out by the microwave method for the first time.PubDate: 2017-09-12DOI: 10.1007/s40242-017-7112-z

Authors:Xueqin Cui; Zhongxiao Ma; Lu Bai; Yong Wu; Sen Guo; Qingchao Liu; Li Zhang; Chi-Tang Ho; Naisheng BaiAbstract: Abstract Leaves of Ziziphus jujuba Mill.(Z. jujuba) were used as a folk medicine to treat children suffering from typhoid fever, furuncle and ecthyma in China. The present study was to establish a high performance liquid chroma-tography-diode array detector(HPLC-DAD) method for quality control of Z. jujuba leaves. The validated method was applied to the simultaneous characterization and quantification of sixteen main constituents in thirty samples, which comprised the whole life stage of Z. jujuba leaves from six cultivars in Yulin, Shannxi Province, China. HPLC fin-gerprint file of Z. jujuba leaves was set up and the results indicate that the major constituents of Z. jujuba leaves are (‒)-catechin(1), quercetin-3-O-robinobioside(3), rutin(4) and quercetin-3-O-α-L-arabinosyl-(1→2)-α-L-rhamnoside(6) with the total contents of the nine flavonoids in respective batch ranging from 18.52 mg/g to 39.51 mg/g. In addition, the contents of compounds depend on both the season and the cultivar. During ripening of Z. jujuba leaves, flavo- noids of all the cultivars present a similar trend: initially decrease from 25th, Jun. to 5th, Aug., 2015, and then in-crease for a period of time, finally slightly fluctuate on 5th Oct. The highest contents of total flavonoids were regis-tered on 25th Jun., 2015. Different cultivars have 50%―90% variation on the content for the three classes of com-pounds. Taken together, the results demonstrate that Z. jujuba leaves have great potential to be a new health-promoting resource based on flavonoids and the best sampling time of them is in June.PubDate: 2017-09-12DOI: 10.1007/s40242-017-7076-z

Authors:Dan Zhu; Wei Jin; Bingwen Yu; Yangwei Ying; Haixiang Yu; Jin Shan; Yuwei Yan; Chen Xu; Baolai Wang; Qinhan JinAbstract: Abstract Traditional low power-microwave plasma torch(MPT) excitation source of atomic emission spectrometry was shown to be good for the introduction of dry aerosols, but poor for wet sample aerosols. In this work, some significant modifications have been made to traditional MPT. A new MPT excitation source working at kilowatt microwave power has been developed. The kilowatt MPT source can sustain stable plasmas with double or even more filaments, presenting a “bell” form, where the region around the converging point is the optimum region for analysis. The tolerance to aqueous aerosol of the torch is enhanced significantly compared to the traditional one. Therefore, the desolvation system that the low power MPT source has to be relied on can be gotten rid of. A set of favorable detection results have been obtained with direct wet sample aerosol introduction. The kilowatt MPT source is expected to become a practical excitation source for atomic emission spectrometry that will be widely used.PubDate: 2017-09-11DOI: 10.1007/s40242-017-7072-3

Authors:Yaozhu Wei; Xiangshi TanAbstract: Abstract The human pathogen Clostridium difficile infection(CDI) is one of the most important healthcare-associated infections. Methyltransferase(MeTrCd) and corrinoid iron-sulfur protein(CoFeSPCd) are two key proteins in the acetyl-coenzyme A synthesis pathway of Clostridium difficile, which is essential for the survival of the pathogen and is absent in humans. Hence, the interaction between MeTrCd and CoFeSPCd can become innovative targets for the treatment of human CDI. In this study, the interaction between MeTrCd and CoFeSPCd was verified by fluorescence resonance energy transfer measurements. The influence of the interaction on the tertiary structure of MeTrCd and CoFeSPCd was studied by ANS-labeled fluorescence measurements. Molecular docking was also performed to understand the mechanism of the protein interactions. These results provide a molecular basis for innovative drug design and development to treat human CDI.PubDate: 2017-09-11DOI: 10.1007/s40242-017-7142-6

Authors:Jia Feng; Xiuqing Shao; Zhuobin Shang; Jianbin Chao; Yu Wang; Weijun JinAbstract: Abstract A new and efficient fluorescent sensor 4′-hydroxy-3′-[(4-antipyrineimino)methyl]-4-biphenylcarboni- trile(L) was prepared for the selective detection of Zn2+ in aqueous ethanol medium. When excited at 419 nm, the fluorescent intensity of sensor L at 507 nm was remarkably increased more than 54-fold after adding Zn2+ ions. The strong green emission of the solution can be easily identified by naked eye under UV light. Thus, sensor L behaves as a naked eye fluorescent “turn on” detector for Zn2+ ions. The fluorescence enhancement might be attributed to the in-hibition of excited state intramolecular proton transfer(ESIPT) and C=N isomerization as well as the chelation en-hanced fluorescence(CHEF) effect. The complex solution of sensor L with Zn2+ ions exhibited reversibility with ethylene diamine tetraacetic acid(EDTA) and the probe could be recycled for further use. Notably, sensor L could clearly distinguish Zn2+ from Cd2+. The interaction of sensor L with zinc ions was investigated by means of FTIR, 1H NMR and HRMS spectroscopy. Furthermore, sensor L has been applied for cell imaging studies.PubDate: 2017-09-11DOI: 10.1007/s40242-017-7084-z

Authors:Zhongcheng Liu; Yanfen Zhang; Yao Xie; Ying Sun; Kewei Bi; Zhe Cui; Lijian Zhao; Wufang FanAbstract: Abstract An aptamer-based colorimetric biosensor was developed, which could be used to detect residual strepto-mycin from food quickly and cost-effectively. The ssDNA aptamer target for streptomycin was obtained using sys-temic evolution of ligands by exponential enrichment through affinity chromatography. A total of 19 candidates were obtained after 10 rounds of selection and were grouped into 3 families according to their similarity of sequence and structure. Among them, aptamer A15 showed the highest affinity for streptomycin tested by fluorescence intensity analysis with a dissociation constant of 6.07 nmol/L. Aptamer A15 also exhibited a higher streptomycin specificity with the lowest detectable limit of 25 nmol/L according to the value of A 620/A 520 ratio with AuNP-based colorimetric assay. The method was specific and sensitive for the detection of streptomycin from simply-treated milk and honey at 100 and 125 nmol/L, respectively, and is a promising approach to monitor antibiotics or other small molecules ana-logues in food inspection.PubDate: 2017-09-11DOI: 10.1007/s40242-017-7029-6